I apologize if this is not an appropriate question. I'm not really sure where to ask or who to trust.
I have a basement that the ultimate plan is to put epoxy, but before we can get to that stage, the crumbling cement needed to be dealt with. So an epoxy contractor was hired and he hired a subcontractor for installing cement to attack the area with the problem. The subcontractor is apparently a masonry company looking at their uniform.
The new cement was installed on top of the old floor. They did told me that there is an acidity problem, so they installed a metal mesh drilled into the old floor to allow better adhesion.
It the cement was added last Saturday. Today (Tuesday, August 29th), I am seeing hairline cracks forming. Pictures in the link
https://i.stack.imgur.com/YYkgP.jpg
I already contacted a friend who is a masonry contractor (but didn't hired him because was a small job and didn't look interested in taking the job) and he told me they did a bad job. Telling me to go get a refund and have to re-do the project. But I'm still hoping against hope that it more of a different in opinions in construction or maybe other motives.
There's also the factor the cracks may not be their fault but my/our own. I have tenants in the basement. Despite repeated instructions to not put anything heavy when they return Monday, they put something heavy (maybe it is not that heavy as two strong people can pick it up, but way heavier than a table or a person continuously walking around). I caught it in the evening and moved it off, but it was there.
So all that said, is the hairline cracks something to be concerned? Is it so problematic that it has to be redone/demand-a-refund per masonry friend's advice? Or it is acceptable enough to go forward in after a few weeks for epoxy? And if the later, then what of the masonry friend's advice?